Volume 17, Number 9—September 2011
Dispatch
Q Fever among Culling Workers, the Netherlands, 2009–2010
Jane Whelan
, Barbara Schimmer, Peter M. Schneeberger, Jamie Meekelenkamp, Wim van der Hoek, Mirna Robert–Du Ry van Beest Holle, and Arnold IJff
, Barbara Schimmer, Peter M. Schneeberger, Jamie Meekelenkamp, Wim van der Hoek, Mirna Robert–Du Ry van Beest Holle, and Arnold IJff
Table 2
Variables associated with Q fever seroconversion among 246 workers who were seronegative before culling small ruminants, the Netherlands, 2009*
| Variable | No. (%) workers |
Univariable analysis |
Multivariable analysis† |
|||||
|---|---|---|---|---|---|---|---|---|
| Total | Seroconversion | RR (95% CI) | p value‡ | RR (95% CI) | p value | |||
| Total |
246 (100) |
43 (17) |
||||||
| Sex | ||||||||
| F | 6 (2) | 2 (33) | Reference | |||||
| M |
240 (98) |
41 (17) |
0.51 (0.16–1.64) |
0.301 |
||||
| Age, y | ||||||||
| <45 | 96 (39) | 14 (15) | Reference | |||||
| >45 |
150 (61) |
29 (19) |
1.33 (0.74–2.38) |
0.339 |
2.0 (0.93–4.16) |
0.07 |
||
| Level of education | ||||||||
| Low | 39 (21) | 5 (13) | Reference | |||||
| Medium | 103 (55) | 18 (17) | 1.36 (0.54–3.42) | |||||
| High |
44 (24) |
8 (18) |
1.42 (0.51–3.98) |
0.765 |
||||
| Minimum distance of residence from nearest infected farm, km | ||||||||
| >5 | 174 (73) | 32 (18) | Reference | |||||
| <5 |
63 (27) |
9 (14) |
0.78 (0.39–1.53) |
0.460 |
||||
| Medical history§ | ||||||||
| No | 128 (75) | 23 (18) | Reference | |||||
| Yes |
42 (25) |
5 (12) |
0.66 (0.27–1.63) |
0.358 |
||||
| Current or past smoker | ||||||||
| No | 84 (44) | 16 (19) | Reference | |||||
| Yes |
108 (56) |
16 (15) |
0.78 (0.41–1.46) |
0.435 |
||||
| Total hours worked inside farm perimeter¶ | ||||||||
| 0–20 | 81 (33) | 5 (6) | Reference | Reference | ||||
| 21–100 | 82 (34) | 18 (22) | 3.56 (1.39–9.12) | 5.53 (0.71–42.77) | 0.102 | |||
| >100 |
80 (33) |
20 (25) |
4.05 (1.60–10.26) |
0.003 |
7.75 (1.02–58.99) |
0.048 |
||
| Mean farm size >1,500 animals# | ||||||||
| No | 167 (68) | 22 (13) | Reference | |||||
| Yes |
79 (32) |
21 (27) |
2.02 (1.18–3.44) |
0.010 |
1.75 (0.93–3.30) |
0.081 |
||
| Worked mostly inside stable | ||||||||
| No | 110 (45) | 11 (10) | Reference | |||||
| Yes |
133 (55) |
31 (23) |
2.33 (1.23–4.42) |
0.006 |
2.58 (1.04–6.37) |
0.040 |
||
| Animal abortions on farm | ||||||||
| No | 208 (85) | 33 (16) | Reference | |||||
| Yes |
38 (15) |
10 (26) |
1.66 (0.89–3.07) |
0.119 |
0.93 (0.45–1.91) |
0.844 |
||
| Any previous culling experience | ||||||||
| No | 85 (43) | 15 (18) | Reference | |||||
| Yes |
114 (57) |
17 (15) |
0.84 (0.45–1.59) |
0.603 |
||||
| Adherence to hygiene and preventive measures** | ||||||||
| Fully compliant | 91 (50) | 13 (14) | Reference | |||||
| Not compliant |
91 (50) |
17 (19) |
1.31 (0.68–2.53) |
0.424 |
0.94 (0.51–1.72) |
0.829 |
||
| Months spent culling | ||||||||
| Dec 2009–Mar 2010 only (mean temperature 3.2°C) | 105 (54) | 18 (17) | Reference | |||||
| Apr–Jun 2010 only (mean temperature 13.9°C) | 2 (1) | 1 (50) | 2.92 (0.69–12.41) | |||||
| Dec 2009–Jun 2010 | 87 (45) | 21 (24) | 1.41 (0.80–2.47) | 0.288 | ||||
*Total for each category may be <246 because of missing data. RR, risk ratio; CI, confidence interval.
†All data available for n = 180 in multivariable analysis.
‡Pearson χ2.
§History of cardiorespiratory disease, liver disorders, diabetes, cancer, immunosuppression, allergies, skin conditions.
¶Data only available for n = 194, those who worked inside the farm perimeter.
#Weighted mean number of animals on farms worked by participants.
**Includes wearing mask, gloves, overalls, hairnet, showering after exposure.
Page created: September 06, 2011
Page updated: September 06, 2011
Page reviewed: September 06, 2011
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